Baunoch D A, Xu M, Tewari A, Christman J K, Lane M A
Laboratory of Molecular Genetics, Michigan Cancer Foundation, Detroit 48201.
Oncogene. 1992 Nov;7(11):2351-3.
The monoclonal antibody (mAb) 1801 has been reported to identify an N-terminal determinant within the tumor-suppressor protein p53 located between amino acids 32 and 79. This region contains two potential sites for serine phosphorylation at amino acids 33 and 46. Using a novel technique which dephosphorylates proteins in situ in fixed permeabilized cells, we have unmasked determinants in p53 recognized by mAb 1801, allowing additional sites of p53 protein to be detected in immunohistochemically reacted cells. This result indicates that phosphorylation at one or both sites within the determinant recognized by mAb 1801 previously blocked antibody-ligand interaction. It further suggests that in situ dephosphorylation may be of more general use in identifying antibodies which can only bind to epitopes in a particular phosphorylation state.
据报道，单克隆抗体（mAb）1801可识别肿瘤抑制蛋白p53中位于氨基酸32至79之间的N端决定簇。该区域在氨基酸33和46处含有两个潜在的丝氨酸磷酸化位点。我们使用一种在固定通透细胞中原位使蛋白质去磷酸化的新技术，揭示了mAb 1801识别的p53中的决定簇，从而能够在免疫组织化学反应的细胞中检测到p53蛋白的其他位点。这一结果表明，mAb 1801识别的决定簇内一个或两个位点的磷酸化先前阻断了抗体 - 配体相互作用。这进一步表明，原位去磷酸化在鉴定只能结合特定磷酸化状态表位的抗体方面可能具有更广泛的用途。
